In a related art example of an antenna device formed so that an antenna can be moved pivotally on an antenna base member and, moreover, retained in a predetermined posture, a pivot is passed through each of a fixed clutch plate secured to the antenna base member and having recesses and projections like those of a clip washer, and a movable clutch plate secured to a base end portion of the antenna and having recesses and projections like those of a clip washer, and the movable clutch plate is elastically engaged with the fixed clutch by a compression coiled spring loosely fitted around the pivot. Since the recesses and projections of the fixed clutch and movable clutch are meshed with one another, a predetermined posture of the antenna is retained. When the disengaging of the recesses and projections of the fixed clutch plate and those of the movable clutch plate from one another is done against an elastic force of the compression coiled spring, the antenna can be turned.
However, in this related art antenna device, the number of parts of a mechanism for retaining the antenna in a predetermined posture including the fixed clutch, movable clutch and compression coiled spring is large. This causes the construction of the related art antenna device to become complicated, and the weight thereof to increase.
Therefore, the present invention has been made in view of such circumstances, and aims at providing an antenna device having a simple construction of the mechanism for retaining the antenna in a predetermined posture.